Abstract

Materials and methods: In the pilot study, 100 students returned completed forms containing the Multi Dimensional Health Locus of Control (MHLC) and the (SILOC) scale. In the main study, 509 adolescent school children from three schools returned completed forms containing the SILOC scale and were examined for oral health status and dental attendance.

Results: The SILOC scores highly correlated with the MHLC scores. A Cronbach’s alpha of 0.75 showed its internal consistency. Those with higher SILOC scores had greater levels of caries, plaque, gingivitis, and a history of postponing needed dental visits. Multiple logistic regression analysis after adjusting for potential confounders showed that those with high SILOC scores were more likely to be having caries (OR=3.32, p<0.001), plaque (OR=1.83, p=0.026), gingivitis (OR=1.80, p=0.012) and a history of ‘Postponement of needed dental treatment’ (OR=4.5, p<0.001) as compared to the others.

Conclusion: The SILOC scale showed satisfactory reliability and validity in measuring Locus of Control orientation in relation to socio-dental impacts in an Indian adolescent population.

Keywords

Socio-dental impacts; Locus of Control

Introduction

Health Locus of Control (HLC) is a construct that refers to how
individuals perceive the sources regulating their health [1]. It is a
product of Rotter’s [2] social learning theory, which states that “an
individual learns on the basis of his or her history of reinforcement”.
Through a learning process, individuals will develop the belief that
certain outcomes are a result of their action (internals) or a result of
other forces independent of themselves (externals). Early HLC studies
measured these beliefs on an Internal-External axis [3]. This scale of
health beliefs ranged from Internal HLC, where control for one’s health
resides within the individual, to External HLC, where control resided
elsewhere. Levenson [4] argued that understanding and prediction
could be improved by studying fate and chance expectations separately
from external control and powerful others and offered an alternative
model that asserts that there are three independent dimensions:
Internality, Chance, and Powerful Others. According to Levenson’s
model [4], one can endorse each of these dimensions of locus of control
independently and at the same time. Although these three dimensions
are traditionally treated as independent, studies have revealed
correlations between the three factors [5,6].

This approach to social cognition models has been criticized for
taking too narrow an approach to health and because the amount of
variance explained is low [7]. Several researchers have used the basic
scales but found the scales needed to be modified to measure specific
diseases or conditions such as diabetes, headaches, and adolescent depression [8-10].This was successful within the context used in
individual studies. However, because each study adapted the scales
differently, little comparison between studies is possible [11]. Another
disadvantage is that, although the multidimensional scales provide
more in depth assessment, they take more time to administer, and are
difficult to score in a clinical setting [12]. Previous studies have shown
a relationship between locus of control and oral health status, but the findings have been contradictory [11,13,14]. Similarly previous studies
have shown a relationship between locus of control and oral health
behaviors as well [15-18] but with equally contradictory results [19-21].

These contradictory results could be due to a ‘one size fits all’
approach to the use of Generic Locus of Control (LoC) scales across
different clinical situations and cultures. Some studies suggested that
people’s general health beliefs were inherent to their culture and played
a key role in influencing their health care seeking and health behaviors
and hence, any health intervention must factor in, an understanding
of culture, tradition, beliefs, and patterns of family interactions [22].

A flexible locus of control scale specific to oral health that can be
modified in accordance with cultural beliefs of the target population
has not been previously reported in the literature. Such a scale can
be of help for oral health planners in deciding the type and level of
intervention required to bring about a positive change in oral health
attitudes in specific populations. While numerous scales that use the
socio-dental approach for needs assessment have been developed,
no attempt has been made to assess the locus of control in terms of
socio-dental impacts. The objectives of this study were to develop a Socio-Dental Impact Locus of Control (SILOC) scale and to study the
relationship between SILOC scale and oral health status.

Materials and Methods

This study was done among school going adolescents aged 15-17
years, of Udupi district in the coastal region of South India. It consisted
of two parts: the pilot study for validation of the SILOC scale and the
main study to evaluate the association between SILOC and oral health
status.

Pilot study

The theoretical framework for the proposed questionnaire was
derived from the WHO International classification of functioning,
disability and health [23]. The definition and sub categorization of
‘Disability’ was considered as per the International Classification of
Diseases. Disability was an umbrella term for impairments, activity
limitations and participation restrictions caused by, in our case, poor
oral health. ‘Impairment’ has been defined as a loss or abnormality in
body structure or physiologic function, in our case, of the oral cavity.
‘Activity limitations’ are difficulties faced by an individual in doing
routine activities and ‘Participation restrictions’ are the problems a
person may face in involving himself or herself in life situations and
interacting with the society, which is otherwise considered normal for
a healthy individual, because of poor oral health.

A 15 item SILOC questionnaire was initially developed. This
questionnaire was translated independently twice into the local
language, first by a dentist with extensive knowledge of both English
as well as the local language and second, by a professional translator.
Both translations were merged into one version. This version was back
translated into English to test the conceptual validity. However since
translation alone did not ensure that the local version was culturally
appropriate, qualitative interviews with a focus group of 20 respondents
were conducted to establish the conceptual equivalence and content
validity of the SILOC.

Validation was done by conducting a study among 120 adolescents
of 15-17 years age, studying in a pre-university college in Udupi
district. After discounting those who returned incomplete forms or
refused to participate, the sample size consisted of 100 adolescents.
The adolescents were administered the Socio-Dental Impact Locus
of Control Scale (SILOC) and a previously validated Indian version
of the Multidimensional Health Locus of Control Scale (MHLC) for
assessing criterion validity [24]. Responses to the items were analysed
to identify which items may be dropped from the scale. When there
was high correlation between similar items, one item was removed
after examining its effects on the scale’s internal consistency.

The final version of the SILOC scale contained seven items (Table 1). The first two items of the final questionnaire assessed the level
of the individual’s ownership for his or her oral health status; items
three and four, for the impairment caused by caries or missing teeth or periodontal disease, item five, for the oral activity limitation, and
items six and seven for the restriction in participation and interaction
with the society caused by poor oral health. The responses were in the
Likert format (1 to 5) with the lower scores signifying ‘internality’ and
the higher scores pointing to an ‘external’ locus of control. The scoring
range ranged from seven to thirty five.

Main study

The target population for the second part of the study consisted
of 630 adolescents aged 15-17 years, attending three pre-university colleges, one each from the three administrative zones of Udupi District.
All the students who were present on the day of the examination were
invited to participate in the study. After discounting those who were
not present on the day of the examination and those who refused to
give informed consent, the final sample size was 509 students. Ethical
Clearance was obtained from the Kasturba Hospital ethics committee
prior to the study.

The participating adolescents were subjected to an interview,
where, in addition to their socio demographic data and previous dental
treatment history, the Socio-Dental Impact Locus of Control Scale
(SILOC) was administered. The participants were later subjected to
a clinical examination where caries, plaque and gingival status were
assessed. Socioeconomic status was assessed by using the revised
Kuppuswamy Scale [25]. This widely used Indian scale, divided the
population into 5 groups ranging from 1; the highest SES group to 5;
the lowest, based on their educational level, occupation and income.
Dental attendance was assessed by asking a single question as to
whether the respondent had previously postponed visiting the dentist
for getting needed dental treatment. We hypothesized that those with a
more external locus of control would show irregular dental attendance.

The sample population was subjected to a whole mouth clinical
examination where they were examined for dental caries [26], plaque
and gingivitis. Plaque was considered as present, if it was seen visibly or
by probing with an explorer on any of the tooth surfaces in the mouth.
Bleeding on probing was considered as an indication of gingivitis, if
observed along any tooth surface of the mouth. Furthermore, the level
of plaque and gingivitis was quantified by measuring them according
to the criteria of the plaque and gingival index [27,28]. The tooth worst
affected by plaque accumulation and gingival bleeding was considered
for the quantitative assessment. The grading for plaque and gingivitis
ranged from 0 to 3 respectively.

Statistical analysis

Cronbach’s Alpha was used to measure the internal consistency
of the questionnaire. Spearman’s Rank correlation coefficient was
used to correlate the SILOC scores with MHLC scores. Paired ‘T’ test
was used to compare the SILOC scores when checked for test retest
reliability and also against oral health status. The interquartile range of
the respondent scores for the SILOC was used to classify the population
into Low, Moderate and High LoC groups. ANOVA with Tukey’s post
hoc was also used to compare the mean SILOC scores against oral
health status. To study the association between Locus of Control and
oral health status and dental attendance, a multiple logistic regression
model was employed. All the statistical analysis was done with SPSS
version 16 (SPSS Inc, Ill, Chicago, USA). A p value of ≤ 0.05 was
considered statistically significant.

Results

Pilot Study

The mean MHLC scores for Internal, Powerful and Chance locus
of control was 25.36 ± 6.50, 17.8 ± 7.3 and 16.8 ±6.29 respectively.
The mean SILOC score was 8.39 ± 3.40.The correlation coefficient
between the SILOC and Internal, Powerful and Chance locus of
control of MHLC was found to be -0.317 (p= 0.001), 0.192 (p=0.055)
and 0.471(p<0.001) respectively. The SILOC scores were classified into
Low (≤ 7), Moderate (8-10) and High (≥ 11) for comparing against the
mean Internal, Powerful others and Chance scores of the MHLC. We
found that the mean Internal LoC was highest (26.73 ± 6.29) for the
‘Low’ SILOC group and the mean ‘Chance’ LoC was lowest (16.09 ± 6.30) for the ‘High’ SILOC group as shown by ANOVA and post hoc
tests (Table 2).

No.

Items

1

Who is responsible for keeping my teeth healthy?

2

If I have good oral health, who should get the credit?

3

If I get tooth decay or ache, who is to blame?

4

If I have missing teeth, or sensitive teeth or bleeding/ swollen gums, who is to blame?

5

If I have difficulty in eating, speaking, chewing and enjoying food because of problems with my teeth or mouth, who is to blame?

6

If I have difficulty in smiling, mixing with friends or indulging in social activities because of problems with my teeth, who is to blame?

7

If people make fun of me because of the condition of my teeth and mouth, who is to blame?

Scores

Responses

1

Only me, no one else.

2

Mainly me, but also my family*, teachers, dentist and friends to a small extent

3

Mainly my family*, teachers, dentist, and friends but also to a small extent, myself

4

Mainly fate or god but also my family*, teachers ,dentist and friends to a small extent

5

Fate or god only. Definitely not me

(*) =Family, as in Parents, grandparents, siblings, and other relatives.

Table 1: The Questionnaire items and responses for the SILOC scale.

MHLC Scales

SILOC Scores

N

Mean

SD

p-value

post-hoc test

Internal

Low

77

26.73

6.29

<0.001

Low> medium, high

Medium

10

21.60

6.75

High

13

20.1

3.21

Chance

Low

77

16.81

6.23

0.277

NA

Medium

10

14.80

6.71

High

13

19.00

6.16

Powerful others

Low

77

16.09

6.30

<0.001

High>Low

Medium

10

20.30

8.72

High

13

26.00

5.90

p=0.05: Significant.

Table 2: Relationship between MHLC scores and the SILOC scores in the study population.

The questionnaire was re-administered to a group of 20 children
after a week for test retest reliability. The mean SILOC score of the
group at the test and retest stage was 8.68 ± 2.85 and 8.04 ± 2.03
respectively, the differences between which were not statistically
significant. Also a statistically significant correlation (r= 0.72, p<0.001)
was found between the two sets of responses. The Cronbach’s alpha
for the SILOC was 0.75.The examiners underwent calibration training
for the clinical indices under the supervision of an expert. The Kappa
coefficient for intra and inter examiner variability ranged from 0.78 to
0.92 respectively.

Main study

The sample population consisted of 509 students whose age ranged
from 15 to 17. The frequency distribution of the students’ variables
showed that 77.4% belonged to the lower socioeconomic status,
and 71.1% had plaque and 42% had gingivitis. Although the caries
prevalence was 52.25%, a majority of the students had DMFT scores
of less than five. SILOC scores were classified into Low (≤ 7), Moderate
(8-10) and High (≥ 11) and the proportion of the population in these
three groups were 45.4%, 22.58% and 31.8% respectively. A majority
of the adolescents (76.8%) reported that they had postponed visiting a
dentist for getting dental treatment.

Mean SILOC scores were compared against caries, plaque,
gingivitis experience as well as Socioeconomic Status (SES) and
‘postponement of dental treatment’. We found that the mean SILOC
scores were significantly higher among those with caries (p<0.001),
plaque (p<0.05), gingivitis (p<0.05) and those who admitted that they had postponed getting needed dental treatment (p<0.001). Males
reported significantly higher SILOC scores than females (p<0.001)
(Table 3).

Multiple logistic regressions was done to study the role of SILOC
as a risk indicator for oral problems like caries, plaque accumulation,
gingivitis and also ‘postponement of dental treatment’ after adjusting
for possible confounders like age, gender and socioeconomic status
(Table 4). Those with high SILOC scores were significantly more likely
to be having caries (OR=3.32, p<0.001), plaque (OR=1.83, p=0.026),
gingivitis (OR=1.80, p=0.012) as well as a history of ‘postponement of
needed dental treatment’ (OR=4.5, p<0.001) as compared to the others.

Discussion

The objectives of this study were to develop an socio-dental impact
locus of control scale (SILOC) which was short, easily adaptable to
different age groups and populations, that combined the advantages
of the one-dimensional and multidimensional scales by incorporating
the three sub categories of Internal, Powerful others and Chance in a
one-dimensional scale and to study the relationship between SILOC
and oral health status and attendance (as assessed by the respondents’
history of postponing visiting the dentist for getting needed dental
treatment) in an Indian population.

Our study showed the SILOC to be valid and reliable to assess
the locus of control orientation of an Indian adolescent population.
A more external locus of control as shown by higher SILOC scores
was associated with higher dental neglect, caries, and plaque and
gingivitis prevalence as well as with a tendency to postpone needed
dental treatment. Previous research has shown that an external locus of
control was associated with poorer oral health indicators [11,13,14] as well as poorer dental attendance [17,29,30], which were in agreement
with the findings of our study. These factors were considered for
validation of the SILOC as they have been shown to be associated with
locus of control in the past. Females demonstrated lower SILOC scores
signifying greater internality than males which were in agreement with
the findings reported by Peker and Bermek [30]. These findings may be
explained by the fact that females tend to have better health compliance
than males.

Some of the possible advantages of the SILOC scale are that, it can
be adapted for use in different age groups and cultures by modifying
the responses. For example, in our study, for ‘Powerful others’, we
included the ‘family, teachers, friends and dentist’ as people who would
wield a powerful influence on their lives. Family was an umbrella term
which included parents, grandparents, siblings and other relatives. The
reason for this was the fact that the extended family occupies a central
position in Indian society by providing material, moral and emotional
sustenance and support to all its members. Hence the role of the family
influence on individual attitudes cannot be overestimated. Similarly, for ‘Chance’ LoC, the responses were ‘Fate’ and/or ‘God’. An individual
who has an external locus of control would blame his fate for his oral
problems. Other cultures may have different people or concepts to fit
into the ‘Powerful others’ and ‘Chance’ LoC and the responses can be
modified to suit them. The responses were negatively worded as “who
is to blame” rather than a more neutral” Who is responsible”, as both
are used interchangeably in the local language and roughly carry the
same meaning. Since the study population consisted of adolescents, it
was thought as more appropriate to use the negative response to reflect
the adolescent angst.

This study constituted an attempt to develop a simple, short, likert
scale to assess the LoC orientation of a target population in relation to
socio-dental impacts, so as to help planners design specific interventions
to reduce the oral disease burden. It would be inappropriate to place too
much importance to locus of control as the most important construct
to predict health attitudes and behavior and besides, early studies have
shown that HLC predicted health behaviors only in those who highly
valued their health [31,32]. However it has to be conceded that since
this study had a cross sectional design, it is difficult to establish a causal
relationship between the SILOC and the socio demographic and oral
health indicators and behaviors. Furthermore, the long term stability
of the SILOC orientation of a target population obtained by our scale is
yet to be ascertained through longitudinal studies. Further research is
needed to validate this scale in different cultures and age groups.